UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study

Inclusion Criteria

• Age 18-40
• In good health, determined by the PI on the basis of medical history and a standard assessment for anesthesia to be documented as part of the study record
• Right handed, to standardize for asymmetry in brain functions

Exclusion Criteria

• Adults 40 years old
• Pregnancy confirmed on pregnancy test on day of sedation
• Contraindication to anesthesia or allergy to study drug
• Difficult anesthesia: American Society of Anesthesiologists Physical Status greater than 1, per the discretion of the PI. Examples of ASA status include, but are not limited to:
• Any systemic disease present, such as diabetes, cardiac, pulmonary, or other acute or chronic disorder, or history of smoking
• Narrow angle glaucoma
• Abnormal airway examination
• Any abnormality on medical history and physical examination
• Snoring or sleep disorders including apnea
• Antecedent pulmonary aspiration risk (e.g., history GI reflux, heartburn, hiatal hernia)
• Adverse reaction or allergy with anesthesia or other sedatives
• Chronic medication use
• History of difficult anesthesia, laryngoscopy or intubation
• Family history of difficulty with anesthesia or sedation
• History of vertigo, nausea or vomiting after anesthesia
• BMI > 35
• Contraindication to HD-EEG, TMS or MRI for relative parts of the procedures. MRI exclusion criteria: presence of metallic or electronic implants; history of claustrophobia. TMS exclusion criteria: Presence or history of medical conditions that could increase the chance of seizures (e.g. - stroke, aneurysm, brain surgery, structural brain lesion) cranial metal implants; structural brain lesion; devices that may be affected by TMS (pacemaker, medication pump, cochlear implant, implanted brain stimulator); history of head trauma with loss of consciousness for greater than 5 minutes; family history of seizures; history of antecedent mood disorder.
• Exclusion from Dexmedetomidine:

o Resting heart Rate<60 bpm

• Exclusion from Propofol:

o Reported egg allergy

• Exclusion from Ketamine:
• History of post-operative nausea and vomiting
• History of motion sickness

Additional exclusion criteria on the day of sedation:

• Anything to eat or drink for the preceding 8 hours
• Any use of over-the-counter or recreational drugs (including alcohol or tobacco) within the preceding 24 hours
• Any use of sedative or sleep agents within the preceding 24 hours
• Recent change in health, including cough, cold, or fever
• Exposure to anesthesia or sedation in the last 6 days